<?php
/**
 * CMysqlColumnSchema class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CMysqlColumnSchema class describes the column meta data of a MySQL table.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CMysqlColumnSchema.php 3204 2011-05-05 21:36:32Z alexander.makarow $
 * @package system.db.schema.mysql
 * @since 1.0
 */
class CMysqlColumnSchema extends CDbColumnSchema
{
    /**
     * Extracts the PHP type from DB type.
     * @param string $dbType DB type
     */
    protected function extractType($dbType)
    {
        if(strncmp($dbType,'enum',4)===0)
        $this->type='string';
        else if(strpos($dbType,'float')!==false || strpos($dbType,'double')!==false)
        $this->type='double';
        else if(strpos($dbType,'bool')!==false)
        $this->type='boolean';
        else if(strpos($dbType,'int')===0 && strpos($dbType,'unsigned')===false || preg_match('/(bit|tinyint|smallint|mediumint)/',$dbType))
        $this->type='integer';
        else
        $this->type='string';
    }

    /**
     * Extracts the default value for the column.
     * The value is typecasted to correct PHP type.
     * @param mixed $defaultValue the default value obtained from metadata
     */
    protected function extractDefault($defaultValue)
    {
        if($this->dbType==='timestamp' && $defaultValue==='CURRENT_TIMESTAMP')
        $this->defaultValue=null;
        else
        parent::extractDefault($defaultValue);
    }

    /**
     * Extracts size, precision and scale information from column's DB type.
     * @param string $dbType the column's DB type
     */
    protected function extractLimit($dbType)
    {
        if (strncmp($dbType, 'enum', 4)===0 && preg_match('/\((.*)\)/',$dbType,$matches))
        {
            $values = explode(',', $matches[1]);
            $size = 0;
            foreach($values as $value)
            {
                if(($n=strlen($value)) > $size)
                $size=$n;
            }
            $this->size = $this->precision = $size-2;
        }
        else
        parent::extractLimit($dbType);
    }
}